What qualifies a bed and breakfast, inn or hotel as "historic"? The only universally agreed-upon criteria appears to be the property being 50 years old or older, which is what we are using for this directory. The degree of further "historical significance" then depends on a multitude of factors, including its association with a locally or nationally famous event or person, being located within the boundaries of a local or national historic district, or was built by a prominent architect or builder, to name a few.